得とく心しんがいくConjugationMeanings1expression, godan verb (iku/yuku class)be convinced; fully understand and agree; be satisfied with an explanationUsed when someone comes to fully accept or understand something, often after receiving an explanation or reasoning. Implies a mental state of agreement and clarity.彼かれの説せつ明めいを聞きいて、ようやく得とく心しんがいった。After hearing his explanation, I was finally convinced.その理り由